Writing on Twitter, the entrepreneur said he was "very supportive of pregnancy leave", and denies the claim he sent an email to a Tesla employee to say he was "extremely disappointed" they could not commit to the event.

Musk has been very vocal on Twitter in the wake of the release of Bloomberg technology reporter Ashlee Vance's new book, which includes a series of quotes and anecdotes from those close to the man behind Tesla Motors, SpaceX, and PayPal.